Ignition system



Feb. 5,1946. 1- wm-rsc 2,394,350

IGNITION SYSTEM Filed June 12, 1941 2 Sheets-Sheet 1 Feb. 5; 1946. M. 'T. WlNTSCH 2,394,350

' IGNITION SYSTEM Filed June 12, 1941 2 Sheets-Sheet 2 Patented Feb. 5, 1946 IGNITION SYSTEM Mai: Theodore Wintsch,-Lancaster, Pa., assignor,

by direct and mesne assignments, of thirtynine and one-half per cent to Newton M. Weaver, and thirteen per cent to Harold Chamberlain. Sn. both of Lancaster, Pa., and ten per cent to Marshall M. Cohen Application June 12, 1941, Serial No. 397,787

2 Claims.

This-invention relates to improvements in ignition systems for-internal combustion engines and more particularly to high frequency electrical ignition systems for automobiles or aircraft engines and the like employing spark plugs for igniting the explosive mixture in the cylinders as well known in the art.

The usual operation of an ignition system for multi-cylinder internal combustion engines includes a timed circuit breaker or interrupter for producing the requisite surge or intensity of electric current at the spark plug gap to ignite the combustion charge in the cylinder. The order of firing the charge in a particular cylinder of a roup is effected by a distributor switch mechanism. One great and common source of difficulty in such systems employing a timer including an interrupter or circuit breaker is that it is a constant source of trouble. This fault is largely due to the fact that the intensity of current required at breaker points is such that it causes them to burn out or deteriorate so that they are frequently in need of repair or replacement. This is particularly true with the present day high speed engines wherein it isnecessary that the spark be accurately timed and of the requisite constant energy strength.

Various types .of ignition systems have therefore been proposed to supply high frequency alternating current directly to the spark plugs of an engine and such form is illustrated in D. W. Randolph et al. Patent No. 2,071,573. However, these systems have likewise been found to be unsatisfactory due to the severe usage and vibrations to which such delicate apparatus is subjected during the operation of the engine, espereliable manner over a wide range of engine op- Referring to Fig. 1 of the drawings there is illustrated a preferred embodiment of a high frequency ignition system constructed and arranged in accordance with the present invention as applied to an ordinary six cylinder internal combus- -tion engine illustrated by the spark gaps i, 2, 3,

l, 5 and t respectively. These spark plug gaps are supplied-with electrical energy by means of a distribution switch indicated by the numeral '5. This switch includes a rotary contact arm 8 driven by an auxiliary engine shaft indicated by the numeral 9 so that the arm wipes over the respeccially in heavy duty automobile and aeroplane installations. One important object of the, present inventio is to provide a novel high frequency ignition circuit system for multi-cylinder internal combustion engines which shall be simple and rugged in construction and more efiective in operation than those heretofore proposed.

Another object of the invention is to provide apparatus of the character designated which shall have a. minimum of moving parts and parts which shall not be afiected by vibration or the usual rough usage incident to the operation of the engines with which it may be associated.

A further object of the invention is to provide a novel form of inductor-alternator and associate circuit for producing and supplying the desired high frequency current in a most emcient and tive contact surfaces i, 2', 3, a, 5 and 6. This is the usual form of distributor and no further description of these parts is deemed necessary as they are standard parts of the usual automobile engine.

The distributor l is supplied with high fre-.

quency alternating current by means of an improved type of high frequency alternating current generator indicated by the numeral 10. This generator is driven at a constant speed by a directly connected D. C. motor indicated by the numeral ii.

One important feature of this arrangement is that the motor i i is operated at a constant speed from a source of current indicated by the battery l2 and is controlled by a convenient switch l3 connected in circuit therewith, independently of any other engine parts.

Connected in circuit with the high frequency alternator i0 is a condenser Id of suitable capacity, in series with the primary 15 of an ignition coil indicated by the numeral 16. This coil 16 also includes a secondary winding H, which is connected in circuit with the arm 8 of the distributor 1, by a lead connection [8. The other side of the secondary is grounded as indicated by the numeral 19 while the spark plug gap circuit is grounded as indicated by the numeral 20.

The operation of the novel ignition system above described is as follows: The high frequency alternating current generator I9 is driven at a requisite constant speed by the direct current motor H or directly by the engine whereby the driving power of the engine is transmitted to the inductor-alternator by means of a constant speed clutch device such as the Allis Eddy current clutch. Therefore high frequency current is thus constantly supplied to the primary coil 45 through the action of condenser I! connected in series therewith. Experience has shown that the inductor-alternator l hereinafter more fully described provides the requisite high voltage and current values desired in an ignition system of this kind. This is .particularly desirable in starting the engine because there are no ignition parts to get out of adjustment as in the case with current interrupters. The closing of the switch 13 starts the motor-generator l0l i to deliver instant full voltage and current intensity to the spark gaps.

One important feature of the present arrangement is that a high frequency alternating current of constant strength regardless of the varying speed of the engine is supplied by the alternator and is always available, to the spark plug gap without the aid of any moving parts which may be affected by electrical energy. This arrangement also eliminates all timing apparatus or circuit breakers heretofore required to discharge the condenser M at the desired interval to complete the circuit through the distributor 1 and thus produce the desired surge potential.

Another important feature of the present construction and arrangement is that the high frequency alternation of current flow at the spark gap prevents fouling of the plug electrodes occasioned by deterioration and accumulation of carbon deposits buildin up on one electrode as is the case with the present day direct current systems. This fouling of the spark plugs and burning away of the electrodes is another great source of trouble in the present day ignition systems.

The fact that current flow is alternating at high' frequency the wear on each electrode terminal v at the gaps is even or uniform.

Referring to the modification shown in Fig. 2, there is shown diagrammatically the specific form of current supply inductor-alternator illustrated in Fig. 1 and a novel ignition circuit arrangement.

In this particular embodiment, the alternator Ill includes six pairs of peripherally disposed permanent magnets indicated diagrammatically by the numerals 2i, 22, 23, 24, 25, and 26. These magnets are preferably made of a high quality coercive power steel such as Alnico metal and support a coil on the core thereof. Each pair of magnets includes a negative pole and a positive pole located on opposite sides of a rotor 21', in-

- dicated in dotted lines, in which there are twelve peripherally disposed and spaced apart pole arms indicated by the numerals 28-28 and which rotor is driven at a constant speed by the motor H. For the purpose of illustration, the positive magnetic poles face the rotor 28 on the left thereof and are in direct linear alignment with each other. The pair of magnet coils mounted on the respective poles are indicated (by the numerals 2|, 22', 23' 24', 25 and 25'.

One importarit feature of this arrangement is that the magnet coils on the right side of the alternator frame are all wound in a clockwise direction and those on the left side are wound in a counterclockwise direction. The individual pairs of opposing coils with their inside leads are connected together serially and all the outside leads of the coils are connected in parallel to the common point of contact. It will be noted that this particular novel arrangement provides for adding the magnetic power output of the twelve permanent magnets thereby maintaining the internal ohmic resistance of the alternator windings at a minimum. The control reactor 21' includes twelve peripherally disposed and spaced apart rotor pole arms indicated by the numeral 28' and rotated by the distributor shaft 9. Associated with the rotor and connected in circuit with the tuned relay 29 are magnet cores supporting coils 45 and 46 mounted on the opposed poles of a per-- manent magnet 41.

Associated with the alternator is a, control reactor 21, a relay 29 tuned by a condenser 39 connected in parallel circuit therewith. Also connected in series with the primary l5 of the coil transformer are condensers 3| and 32. While I have shown one condenser in each circuit it is obviou that these condensers may be replaced by arranging the condensers in groups. The relay 29 is provided with a gravity operated armature 33 which controls the circuit through a contact 34 and the condenser 32 connected in series circuit therewith. It will be noted that the armature 33 of the tuned relay 29 controls the current fiow through the condenser 32 and thus the speed of the control reactor rotor 21' determines the frequency band values of the operating current for the tuned relay 29. The requisite current flow for firing the plugs is maintained at all rotational speeds of the engine as effected by the rotation of the distributor shaft 9 on which the rotor is mounted or directly connected, or is connected thereto by means of a constant-speed clutch device.

For example, when the engine is running relatively slow and the relay coil 29 is energized at the correct or predetermined low band frequency, the armature 33 is maintained closed at contact 34 thus including condensers 3| and 32 in series with the primary coil 15 and thus add their capacities. When the engine speed increases, the

frequency of th alternator reaches a higherband and thus the relay 29 becomes untuned by the action of condenser 39 and the armature 33 opens the circuit contact 34 thereby cutting only the condenser 32 out of the primary coil circuit.

By thus designing the proper values of the coils, condensers and magnetic parts, there is produced an ignition system which is more efficient and reliable in operation than any heretofore proposed.

Referring to Fig. 3 of the drawings there is shown a modified form of ignition system in which pulsating direct current of high frequency and voltage is supplied to the spark gaps through the step-up transformer 16.

In this particular system an inductor-alternator 35 of the same general construction as previously described is used with the exception that th permanent magnet cores for supplying the magnet coils are replaced by 'castiron cores indicated by the numerals 36, 31, 38, 39, 40 and 4|.

The circuit connections are the same as previously described in which the magnet coils on the right side of the stator are wound clockwise and those of the opposing side are wound in a counter-clockwise direction. The individual pairs of opposing coils with their inside leads are connected together in series and all the outside leads are connected together in parallel circuit and connect a common connection point #2 in circuit with the primary winding I5 of the ignition coil or step-transformer.

Direct current is supplied to the indicator coils and the primary winding i5 by a D. C. generator indicated by the numeral 33. .The generator 43 is connected to the coil circuit of the alternator at 44.

One of the important features of the present system is that by providing the alternator windings in the particular manner, the power loss is maintained at a minimum because the ohmic resistance of the winding is low. The fact that the constant direct current of low, voltage is changed to high frequency high voltage pulsating current provides an ignition system or a converter system for commercial use of high efliciency and particularly desirable for certain installation.

Having thus described the preferred embodiment of my. invention, it is obvious that various changes may be made therein without departing from the scope of the invention as specifically set forth in the claims. For example, the number of rotor poles, magnets and coils of the inductoralternator may be changed both in number and character of material.

What I claim is:

1. The combination with an internal combustion engine, of an ignition circuit therefore incircuit therewith, a distributor mechanism inrality of condensers in series-with said transformer, a tuned relay mechanism including a contact connection controlled thereby, a control reactor for energizing said relay and means actuated by said relay for rendering certain of said condensers inoperative when the frequency oi said alternator appreciably is changed by the speed of the distributor, shaft.

2. In an ignition system, the combination with a step-up transformer having a primary winding and a secondary winding connected to an igniting device, of a, high frequency inductor-alternator having a stator composed of a plurality peripherally disposed axially aligned pole members of opposite polarity, magnet coils on each pole membe1,-a toothed rotor passing between the pole meinbers, the coils on one side being wound in clockwise direction and the coils on the other side being wound in counter-clockwise direction, a plurality of condensers connected in'series with the primary of said transformer, a control reactor, and separate means energized by the control reactor at a predetermined speed for rendering certain of the condensers inoperative to maintain the'desired potential on the primary winding over a wide range operating condition.

MAX THEODORE WINTSCH. 

